Method of killing insects with dihydronaphthyl n-methylcarbamate compositions



United States Patent 3,165,442 METHQD F KILLING INSECTS WITH DEHYDRB- I IAPEEHYL N METHYLCAAMATE (ZQWGM- 0N John R. Kilsheirner, South Charleston, W. Va., and Herbert H. Moorefield, Raleigh, N.C., assignors to Union Carbide Corporation, a corporation of New York No Drawing. Original application Dec. 30, 1960, Ser- No. 79,521, new Patent No. 3,081,340, dated Mar. 12, 1963. Divided and this application Dec. 26, 1962, Set.

9 Claims. c1. 167-32) This invention relates to new chemical compounds and to insecticidal compositions containing them, More particularly, this invention relates to hydrogenated l-naphthyl N-methylcarbamates and to insecticidal compositions containing the same; The compounds of this invention are represented by the structural formula:

Hl'l'n O C ONHCH:

wherein n is an integer selected-from the group consisting of 0 and 1. The compounds of this invention are 1-(5,6 I

e-o o-ol 0 OONHCHQ Step A canbe conducted at a temperatureot from I about '3Q ,C. to about 175 C. The reaction can 'be initiated .by.adding pho sgenedissolved in toluene, ben' zene, or'other suitable organic solvent to an aqueous solu- V area -n2 Patented Jan. 12, 1365 tion of the substituted naphthol and sodium hydroxide. The reaction is generally exothermic so that some external cooling is usually necessary. This reaction can be conducted in the presence of other basic compounds in place of sodium hydroxide, such as pyridine and dimethylaniline, to facilitate removal of hydrogen chloride as an organic hydrochloride. In these cases the reaction can advantageously be conducted in solvents such as toluene, dioxane and the like.

Step B can be conducted at a temperature of from about -30 C. to about 100 C. The chloroformate can be added to a solution of methylamine in such solvents as water, benzene, hexane, dioxane and toluene.

The products are crystalline solids which can be separated from the reaction mixture by filtration or centrifugation and dried. I

An alternate procedure for the preparation of the compounds of this invention is by the reaction of the appropriate substituted l-naphthol with methyl isocyanate, as represented by the following schematic equation:

' on oooNrrorr OHgNCO H2 Hz This reaction is conducted by reacting the appropriate naphthol and methyl isocyanate in the presence of an anhydrous inert solvent anda catalyst in a pressure vessel under autogenous pressure and at from about ambient temperatures to about 200 C. The solvent is removed from the reaction mixture by decantation, filtration or distillation and the solid product, primarily the methylcarbamate, can be recrystallized from an organic solvent. The catalyst can be an organo-metallic compound, such as dibutyl tin diacetate or an organic tertiary amine, such as pyridine. Applicable reaction solvents are ethyl ether, benzene, dioxane and the like. The methylcarbamates can be recrystallized from solvents such as xylene, petroleum ether, benzene, methanol and mixtures thereof.

The following examples are illustrative of the preparation of the compounds of this invention: EXAMPLE I.-]-'(5,6-Dihydr0naphthyl) N-methylcarbamate 0 C ONHOHs A mixture of 20 grams of 5,6-dihydro-1-naphthol, 9 grams of methyl isocyanate, 4 drops (approximately 0.2 cc.) of dibu'tyl tin diacetate, and milliliters of ethyl ether was charged to a pressure container and held at ambienttemperature and autogenous pressure for four days. The resulting reaction mixture was removed from the pressure container and was distilled to recover the ethyl ether." The solid residue that remained was re crystallized from a mixture of 50 volume percent of xylenev and 50 volume percent of petroleum ether and dried. The recrystallized product was 1-(5,6-dihydronaphthyl) N-methylcarbramate which melted at C.

. and weighed 24 grams and analyzed as follows: N, 7.0

percent (calculated: N, 6.9 percent).

H2 Amixture of 20 grams of 5,8-dihydro-l-naphthol, 9

grams of methylisocyanate, 4 drops (approximately 0.2

cc.) of dibutyl tindiacetate and 100 milliliters of ethyl ether was charged to a pressure container and was held at ambient temperature and under autogenous pressure for four days. The resulting reaction mixture was removed from the pressure container and distilled to remove the ethyl ether. The solid residue that remained was recrystallized from a mixture of xylene and petroleum ether and dried. The resulting -1-(5,8-dihydronaphthyl) N-methylcarbamate weighed 28 grams, melted at 105 C. and analyzed as follows: N, 6.9 percent (calculated N, 6.9 percent).

' The compounds of this invention are useful as insec ticides. They are particularly effective as insecticides against bean aphids and houseflies, as is illustrated by the following tests.

The compounds are identified in the below-described tests as follows.

Stock formulations of the compounds listed above were prepared by mixing 100 milligrams of the toxicant with 10 milliliters of acetone and 10 milligrams of a dimeric alkylated aryl polyether alcoholcomrnercially sold as a wetting agent. This mixture wasthen diluted with water- Aphid F 'oliag'e Spray Test The test insects were adult and nymph stage'bean aphids (Aphis fabae Scop.) reared on potted dwarf nasturtium plants at a temperature of 65 to 70? F. and a relative humidity of 50 to 70 percent. The aphid populations in the pots were reduced to 100 to 150 individuals per pot by trimming ofi plant containing excess aphids. The pots were sprayed Withtoxicant solution, employing a De Vilbiss spray gun at forty poundspressure, for thirty seconds, in which time 100 to 110 milliliters of the'test solution, an amount sufficient to wet the plants to run-elf, wasapplied. A control solution consisting of 100to 110 milliliters of an aqueous solution of acetone and wetting agent was also sprayed on infested plants. .After spraying, the pots were placed on their sides on a sheet of White paper that had been previously ruled into squares t-ofacilitate counting, and held for twenty-four hours ata temperature of 80 F.:5 F. and a relative humidity of 50 percent :5 percent.- Aphid thathad fallen tothe paper and were unable to remain standing after being uprighted were considered dead, as well as those remaining on the plants that could not move the length-of-the body,'-even upon prodding. f I

The results of-the above-described tests are summarized in Table I below. The mortality figures shown have been corrected forthe mortality rate observed in the controls;

TABLE I LD Values.

mg./l00 ml.

'House Fly Bean Aphid Compound to give 100 milliliters of a standard insecticidal solution.

Lower, graded, test concentrations were prepared by diluting the standard stock solution with water to give the was interpolated from a line drawn throughthe points; so plotted.

Fly Bait Test The test insects were four to six day old adult house flies (Musca domestica L.) that were reared according to the specifications of the Chemical Specialties Manufacturing Association [Blue Book, MacNair-Dorland, Company, New York, pages 243-244, 261 (1954)], at tem- From Table I item be seen'that the compounds of this invention are insecticidally effective toward both bean aphids and house These compounds have also been found to be insecticidally active toward theSouthern armyworm and the Mexican bean beetle. Furthermore, thecompoundsof this invention are stable in the presence of light and air. 1 a i V p The .compoundsof this invention can be applied to plants. or other areasjto be protected by'contacting such area with a compound of the instant'invention in an undiluted form, as a dust when admixed with finely powdered inert carriers,=or in a liquid form. Therate of application can yery'from .about.0.5 to about 5 'pounds of the compound per acre.

perature of 80 F.i2 F. and a relative humidity of percentiS percent.

The adult flies were anesthetized with CO and twenty-five of such flies were placed under a hemispherical wire cage,' -approximately 5 inches in" diameter and 3 inches high, which was inverted over a sheet of white blottingpaper measuring, six inches by six inches, on which was placed a bait cup containing a i V one-inch square pad of a commercially available cellulose absorbent materiaL.

7 .Fifteen milliliters of a test formulation prepared as do. scribed above, to which hadalso been added :10 percent j I on prodding after the twenty-four hour period were con sidered dead. Controls were conducted with solutions prepared as above but without the toxicant.

When the compounds of the instant-invention are ap:

plied as dusts they can be mixed with suitable particulate extenders, such as clay, chalk, talc, diatomaceous earth, pyrophyllite, infusorial earth, fullers earth, pumice, bentonite, and fiours,such as cotton seed flour and walnut The application'of-the instant compounds in'a liquid containing the compounds ofthis invention ispto first pre- 7 a pare a liquid concentrate containing such. compounds by dissolving saidcompounds in a solvent such as acetone, toluene, xylene or kerosene. This liquid concentrate can then be added to water together with suitable surface active dispersing agents whereby-the compoundsofthe instant invention are dispersed in the water. v

A third method of preparing liquid compositions con 'taining theinstant compounds is to prepare a wettable powder by .dispersing said compounds on'or {in a finely divided inert. solid such'asrclay, chalk, talc,. b entonite,

fullers earth and the'like. These compositions may also contain dispersing or wetting agents as desired.' These I compositions can then be mixed with water to provide a liquid insecticide suitable for application to the areas to be treated.

The surface active agents that can be employed in the above-described compositions can be any of the known anionic, cationic, and non-ionic wetting, emulsifying and dispersing agents, such as aralkyl polyether alcohols, aralkyl polyether sulfonates, aralkyl polyether sufates, quaternary ammonium compounds, and the like. When these surface active agents are employed they generally comprise from about 035% to about 5% by weight of the total composition.

This application is a division of application Serial No. 79,512, filed December 30, 1960, now United States Patent 3,081,340.

We claim:

1. An insecticidal composition comprising a compound represented by the structural formula:

H1+n O CO NHCHs Hz wherein n is an integer having a value of from 0 to 1, an insecticidally suitable carrier and a surfactant.

2. An insecticidal composition comprising 1-(5,6-dihydronaphthyl) N-methylcarbamate an insecticidally suitable carrier and a surfactant.

3. An insecticidal composition comprising 1-(5,8-dihydronaphthyl) N-methylcarbamate, an insecticidally suitable carrier and a surfactant.

4. The process for killing insects which comprises applying an insecticidal amount of a compound represented by the structural formula:

Hm, O C ONHCH wherein n is an integer having a value of from 0 to 1, to a locus to be protected.

5. The process for killing insects which comprises applying an insecticidal amount of 1-(5,6-dihydronaphthyl) N-methylcarbamate to a locus to be protected.

6. The process for killing insects which comprises applying an insecticidal amount of 1-(5,8-dihydronaphthyl) N-methylcarbamate to a locus to be protected.

7. The process for killing insects which comprises applying an insecticidal amount of a compound represented by the structural formula:

References Cited in the file of this patent UNITED STATES PATENTS 2,493,710 Aeschlimann et a1 Ian. 3, 1950 2,776,197 Gysin et al Jan. 1, 1957 2,903,478 Lambreck Sept. 8, 1959 2,904,464 Moorefield Sept. 15, 1959 2,904,465 Moorefield Sept. 15, 1 959 FOREIGN PATENTS 578,169 Canada June 23, 1959 

1. AN INSECTICIDAL COMPOSITION COMPRISING A COMPOUND REPRESENTED BY THE STRUCTURAL FORMULA: 